Sheet feeding



cs. w. CHILDS 3,079,149

SHEET FEEDING Feb. 26, 1963 2 Sheets-Sheet 1 Filed May 19, 1961 x InWmmnu...mml W AIR PRESSURE VACUUM /3 INVENTOR '5 33 6 30/39? W 0 VACUUMATTORNEYS Feb. 26, 1963 s. w. CHILDS 3,079,149

SHEET FEEDING Filed May 19, 1961 2 Sheets-Sheet 2 INVENTOR George M/Ckz'lais ORNEYJ 3,79,l49 Patented Feb. 26, 1963 ice 3,37%,149 SEEETFEEDWG George W. Childs, Dallas, Ten, assignor, by mesne assignments, toSperry Rand orporation, New York, N.Y., a corporation of Delaware FiledMay 19, 1961, er. No. 111,258 Claims. 81. 27i27) This invention relatesto material handling and more particularly to an apparatus for pickingup sheets of thin material such as paper one at a time from a stack andfeeding the sheets to a remote location.

In the design of apparatus for performing the function of picking up andfeeding thin sheets one a time to a remote location there have arisenseveral problems, particularly' when it is desired to feed the sheets ata high rate. One problem is a tendency of the apparatus to pick up andfeed more than one sheet at a time from the stack. This particularmalfunctioning is referred to as feeding doubles. Another problem is thesynchronization of the feeding operation so that it is carried outwithout any damage to the thin sheets.

In a copending application Serial No. 53,742 invented by George W.Childs, filed September 2, 1-960, there is disclosed a sheet feedingapparatus which is directed at overcoming these two problems. Thepresent invention is an improvement upon the apparatus in the aforesaidap plication to make the apparatus even more reliable and effective inthe prevention of feeding doubles.

In the apparatus of the aforesaid copending application the sheets to befed one at a time are held in a stack between two guides. A vacuumpickup arm cyclically picks up one sheet from the stack and delivers thesheet to a remote position Where it is accepted between a pair of movingbelts. The apparatus is reasonably effective in the prevention offeeding doubles because it directs a stream of air against the side ofthe stack to riffle and separate the sheets in the stack and becausethere is provided a sheet separating vacuum duct having an openingpositioned adjacent the stack very close to the path that the vacuum armcarries the sheets in moving away from the stack. Air is sucked inthrough the vacuum duct opening and this action causes all the-sheetsbut one carried by the vacuum pickup arm to be removed and left in aposition to be picked up on the next cycle of the arm. The vacuum ductcooperates with the means directing the stream against the stack in thatit tends to hold the edges of the sheets of the stack together while thestream of air separates the sheets in the area adjacent the pickupposition of the vacuum arm.

in the apparatus of the aforesaid copending application there has arisena problem. When the extra sheets carried by the arms 25 are removed fromthe arm by the action of the sheet separating vacuum duct, it ispossible that the sheets removed will close off the opening of thevacuum duct and thus make it ineffective to perform its function. In theimproved apparatus of the present invention this problem is overcome inthat it is made impossible for the sheets removed from the vacuum pickuparm to close off the vacuum duct. Also in the improved apparatus it isless likely that two sheets will be picked up by the vacuum arm in thefirst place.

In the improved apparatus of the invention the vacuum duct itself formsone of the guides between which the stack of sheets is held. The contourof the face of the vacuumduct opening has been modified to be outwardlycurved on the side adjacent to the stack of sheets. Because of thisstructure the edges of the sheets in the stack are drawn together andinto contact with the face of the duct opening. Because of the suckingaction through the vacuum duct opening and the curved face of the ductopening, each sheet in the top of the stack projects out from the stackover the vacuum duct opening slightly more than the adjacent sheetbeneath it. Thus the sheets in the stack are slightly fanned in theregion near the top of the stack with a small margin of each sheet nearthe top of the stack exposed to the sucking action of the vacuum ductopening. Because the sheets are slightly fanned in this manner withtheir edges drawn together into contact with the face of the vacuum ductopening, the vacuum pickup arm is less likely to pick up more than onesheet, particularly since the sheets are separated in the area adjacentthe pickup position of the vacuum pickup arm by the action of the streamof air directed against the side of the stack. The vacuum duct openingextends all the way across the top of the duct. Ribs are provided acrossthe top of the duct projecting away from the edge of the side wall ofthe duct defining the side of the opening remote from the stack. Theseribs prevent sheets from being sucked down into the vacuum duct and alsoprevent the sheets from closing off the duct opening because theyproject away from the edge of the duct side wall. Thus the apparatus ofthe present invention provides more reliable operation in the preventionof feeding doubles by the sheet feeding apparatus.

Accordingly, it is one object of the present invention to provide animproved sheet feeding apparatus.

It is a further object of the present invention to provide moreeffective prevention of the feeding of doubles in sheet feedingapparatus.

It is a still further object of the present invention to provide animproved apparatus for feeding thin sheets froma stack one at a time ata high rate of speed.

Further objects and advantages of the present invention will becomereadily apparent as the following detailed description of a preferredembodiment of the invention unfolds and when taken in conjunction withthe drawings, wherein:

FIG. 1 illustrates a top view of the improved apparatus of the presentinvention;

FIG. 2 is a cross-sectional view of the apparatus taken along the lines22 in FIG. 1;

FIG. 3 illustrates the details of the sheet separating vacuum ductpositioned adjacent the stack of thin sheets and how it operates toelfectively prevent the feeding of doubles; and

FIG. 4 shows the sheet separating vacuum duct in detail.

In the apparatus of the invention as shown in FIGS. 1 and 2, a stack ofthin sheets 11 is held between a guide 13 and one wall 72 of a sheetseparating vacuum duct 15. A bar 19 fixed to the guide 13 extends outover one faceof the stack 11 and an arm 21 mounted on the end of the bar19 extends further out across the stack 11. This face shall be referredto as the top of the stack because the sheets are picked up from thestack at this face. Correspondingly the opposite face of the stack shallbe referred to as the bottom of the stack and the faces of the stackdefined by the sheet edges shall be defined as the sides of the stack.The stack 11 is held between the guide 13 and the vacuum duct 15 bymeans of a spring 17 mounted on the guide 13. The spring 17 bearsagainst the bottom of the stack 11 and urges the top of the stack llagainst the bar 19 and the arm 21. The arm 21 is mounted on the bar 19by means of a pivot 23, which does not permit the arm 21 to rotatefreely, but holds it firmly in position. Adjustment of the position ofthe arm 21 about the pivot 23 determines the precise position of thepart of the top sheet of the stack 11 under the arm 21. A vacuum pickuparm 25 lifts the top sheet from thestack 11 and feeds it between twobelts 27 and 29 which are driven and guided by a system of pulleys 31age mechanism 47 cause all the sheets but one through 4-5. The system ofbelts 27 and 29 and pulleys 31 through 4-5 is substantially identical tothe system of belts and pulleys in the aforesaid copending application.The belt 29 after passing over pulley 45 passes over the puliey 31,where it comes together with the belt 27. The belt 27 after passing overthe pulley 32 comes together with the belt 29 and also passes over thepulley 31. The two belts 27 and 29 lying together then pass over thepulley 33 and then over a series of pulleys 34 through 39 which maintainthe belts 27 and 29 together. The belts 7 and 29 then pass through thepair oi pulleys 4th and Q1. The belt 29 continues around the pulley 41and back to the pulley 45 and the belt 27 passes in the oppositedirection around the pulley 4% and then is guided back to the pulley '52by means oi pulleys 42, 43 and 44.

The arm 25 feeds the sheets from the stack 11 one at a time to the pointwhere the belts 2'7 and 29 come together, whereupon the sheets aregripped by the belts 27 and 29 and are transported by the belts 27 and29 up between the pulleys 4i} and 4-1 where the sheets are fed out ofthe mechanism. The peripheral speed of the pulley 31 and hence the speedor the belts 27 and 29 is controlled to be faster than the speed of thelaterally moving arm 2-5 as it brings a sheet up to the point where thebelts 27 and 29 come together. This feature causes the belts to pull thesheets positively from the arm 25 without any bending or crumpling ofthe sheets by the mechanism. After delivering a sheet from the stack 11to the point where the belts 27 and 29 come together, the arm 25 returnsto the stack 11 where it picks up another sheet.

The arm 25" moves in a straight line motion from adjacent the top of thestack to the point where the belts 27 and 2-9 come together while it iscarrying a sheet and then returns from this point to the pickup positionadjacent the top of the stack in a path which curves away from the stackso that the arm will not tend to make a pickup before it is again incomes to a substantially the pickup position. The arm 25 complete stopeach time it comes to the pickup position adjacent the top of the stack11. The arm 25 is driven in this motion by means of a linkwhich connectsto the arm 25 by means of a pin 49. This linkage mechanism is fullydisclosed in the aforesaid copending application and will not bedescribed in detail here.

An opening 6% is provided in the sheet separating vacunm duct 15. Thisopening is positioned alongside of the top of the stack 11 and races thepath taken by the pickup arm en route to the belts 27 and 29 from thepickup position. The air is evacuated from the interior of the duct bymeans of a vacuum pump withdrawing air from the duct 15 through a tube53. As a result air is sucked in through the opening 69 in the vacuumduct 15. The sheets that are carried by the vacuum pickup arm 25, due tothe motion of this arm in delivering the sheets to the belts 27 and 29,pass close to the opening 69. The air being sucked in through theopening 69 will carried by the arm to be removed from the arm 2%. Thusit it should happen that the arm 28 picks up more than one sheet, theextra sheets will be caused to be removed by the vacuum duct 15. Theseextra sheets will be left in a position to be picked up on the nextsucceeding cycle of the arm 25.

The arm 25 is identical to the one described in the aforesaid copendingapplication and accordingly it will only be briefly described here. Asbest seen in FIG. 2, the arm 25 is formed with two feet 53 and '55. Anopening facing the top of the stack 11 is provided in each of the feet53 and 55. The arm 25 is hollow and telescopes in and out of a tubuiarextension 59 on a hollow cylinder 5-1, which is pivotable about itsaxis. By means of this pivotal motion and the telescoping action of thearm 25 in the tubular extension 59, the arm 25 is made free to move inits cyclical path as it is driven by the mechanism 47. A vacuum iscreated within the cylinder 61 by means of a vacuum pump connected tothe cylinder i 61 through a tube 63, about which the cylinder 61 pivots.The hollow interior of the arm 25 communicates with the interior of thecylinder 61 so that air is sucked in through the openings in the feet 53and 55. Because of the sucking action generated at these openings thearm 25 will pick up the top sheet from the stack 11 each time it comesinto its pickup position adjacent the top of the stack. The two feet ofthe pickup arm straddle the arm 21 when the pickup arm is in its pickupposition and when the pickup arm delivers a sheet between the belts 27and 29 and starts on its return path to the pickup position adjacent thetop of the stack 11, the two feet will straddle the belt and the pulley31, as illustrated in phantom in FIG. 1. The communication between theinterior of the arm 25 and the interior of the cylinder 61 isautomatically closed off when the arm 25 gets to the point where itdelivers a sheet between the belts 27 and 29, as is fully disclosed inthe aforesaid copending application.

Air under pressure is supplied to a separator nozzle 65 which ispositioned to direct a stream of air against the side of the stack 11 inthe area adjacent the pickup position of the arm 25. This stream of airrifiies or separates the sheets in this area and reduces the tendency ofthe arm 25 to pick up more than one sheet.

Although the sheets in the stack 11 are separated in the area adjacentthe pickup position of the pickup arm 25, the edges of the sheetsadjacent the sheet separating vacuum duct 15 are held together by thesucking action of the opening 69. This action of the opening 69 is bestillustrated in PEG. 3. As shown in FIG. 3, the sheets in the stack 11are separated in the area by the reference number 6-7, which is adiacentthe pickup position of the arm 25, by the action of the stream of airdirected by the nozzle 65 against the side of the stack 11. At the sametime the sucking action through the opening 69 holds the edges of thesheets in the stack 11 together. Although this action occurs to someextent in the apparatus of the aforesaid copending application, it ismuch more etlectively carried out by the apparatus of the presentinvention because of the structure and location of the sheet separat ingvacuum duct opening in reference to the stack 11.

As shown in FIG. 3, the wall 72 of the duct 15, which is adjacent thestack ill, is in direct contact with the edge of the stack of sheets illand forms one of the guides between which the stack of sheets is held.The wall 73 of the duct 35, which is remote from the stack 11, extendsfarther than the wall 72. The two edges of these walls define the sidesof the duct opening ea. The ribs 71 and therefore the face of theopening 69 are outwardly curved near the stack 31. The curved portion ofthe face of the opening 6? is positioned adjacent the top of the stack11 between the top and bottom of the stack 11. The edges of the sheetsof the stack l are held in direct contact with the curved portion of theface of the opening 69, or in other words in direct contact with thecurved portion of the ribs 71. Thus the sucking action through theopening 69 is applied directly to the edges of the top sheets in thestack 11 because the edges of the sheets in the stack ill are helddirectly against the face of the opening 69. Because the face of theopening 69 is curved, each sheet near the top of the stack 11 projectsout from the stack 11 over the opening d9 slightly more than theadjacent sheet below it, as is illustrated in FIG. 3. Thus the sheetsnear the top of the stack are slightly fanned with a small margin ofeach sheet near the top of the stack exposed to the sucking action ofthe opening 69. Because the sheets are slightly fanned in this mannerwith their edges drawn together in contact with the opening 69, thevacuum arm 25 is less likely to pick up more than one sheet. The actionof the duct 15 coacts with the action of the separator nozzle 65 in thatit maintains the edges of the sheets 11 together although the sheets areseparated in the area 67. This combined eiiect provides a much morereliable operation in preventing the arm 25 from picking up more thanone sheet from the stack 11 on each cycle.

The fanning of the top sheets in the stack 11 could also be achieved itthe opening 69 had a straight face. To achieve the fanning effect it isonly necessary that the portion of the face of the opening which is indirect contact with the edge of the stack 11 form an acute angle with aplane parallel to the sheets in the stack 11.

As illustrated in FIGS. 3 and 4, the ribs 71 project away from the edgeof the wall 73 as an extension of the wall 73. Because part of the ribs71 are in the plane of the Wall 73 projecting away from the edge of thewall 73, the opening 69 can never be completely closed off by a sheetfrom the stack 11 even if the sheet should extend all the Way across theopening 69 as it quite possibly might do. For example, if the arm shouldpossibly pick up more than one sheet, all of the shectsbut one will becaused to be removed by the sucking action of the opening 69 as the arm25 passes by the opening 69 en route to the point where the belts 27 and29 come together. The sheet or sheets removed by this action could verywell lie all the way across the opening 69. However, the opening 69 willnot be closed off because the structure of the ribs 71 projects. Becausethe opening 69 can not be closed off by overlying sheets from the stack11, the sucking action through the opening 69 will never even betemporarily interrupted.

The position of the arm 21 is adjusted about the pivot 23 so that theopenings in the feet 53 and 55 of the arm 25 will be less thanone-eighth of an inch away from the top of the stack 11 when the arm 2.5is in its pickup position. If the arm 21 is rotated counter clockwiseabout the pivot 23 to depress the top of the stack 11 so that the top ofthe stack is morethan one quarter or" an inch away from the feet 53 and55 when the arm 25 is in the pickup position, a pickup will not occur.Thus the operation of the mechanism can be controlled simply byadjusting the position of the arm 21. A small rotation of the arm 21 ina clockwise direction will start the feeding of sheets from the stack 11and a small rotation of the arm 21 in a counter-clockwise directionuntil the arm 21 is brought into contact with the duct 15 will stop thefeeding operation. The arm 21 may be controlled by a solenoid for remoteor automatic control of the starting and stopping of the feedingoperation.

The above described apparatus is a preferred specific embodiment of theinvention, and many modifications may be made thereto without departingfrom the spirit andscope of the invention.

What is claimed is:

l. A material handling apparatus comprising means to hold a stack ofthin sheets, a vacuum operatedpickup means, means to drive said vacuumoperated pickup means to cyclically move said vacuum operated pickupmeans from a position over said stack to a position remote from saidstack in apredetermined path going away from said stack along a lineinitially parallel to thetop of said stack, said vacuum operated pickupmeans coming to a substantial stop over said stack once each cycle andcausing the top sheet to be picked up from said stack by said vacuumoperated pickup means and carried to said remote position, means toremovefrom said vacuum operated pickup means the sheet carried by thelast said means at said remote position, means defining a ducthaving anopening fixedly positioned adjacent said stack and close but spaced fromsaid path, at least a portion of the face of the opening being curvedand said curved portion being in direct contact with a side of saidstack, means to suck air in through said duct to cause all the sheetsbut the one carried by said vacuum operated pickup means to be droppedfrom the last said means in a position substantially on the top of saidstack to be picked up by said arm on the succeeding cycles of said arm.

2. A material handling apparatus as recited in claim 1 furthercomprising means to direct a stream ,of air against a side of saidstack.

3. A material handling apparatus comprising means to hold a stack ofthin sheets, a pickup arm having a first duct defined in the endthereof, means to suck air in through said duct, means to drive said armto cyclically move said duct from a position over saidstack to apositionremote from said stack in a predetermined path going away from saidstack along a line initially parallel to the top of said stack, saidduct coming to a substantial stop over said stack once each cycle, thesucking action of said duct causing the top sheet to be picked up fromsaid stack by said arm and carried to said remote position, means toremove from said arm the sheet carried by said arm at said remoteposition, means defining a second duct fixedly positioned adjacent saidstack and close to but spaced from said path, said duct defining anopening adjacent said stack, curved rib-like members extending acrosssaid opening at least a portion of said members being in direct contactwith a side of said stack, and means to suck air in through said secondduct to cause all the sheets but one carried by said arm to be droppedfrom said arm substantially on top of said stack in a position to bepicked up by said arm on the succeeding cycles of said arm.

4. A material handling apparatus comprising means to hold a stack ofthin sheets, pickup arm having a first duct defined in the end thereof,means to suck air in through said first duct, means to drive said pickuparm to cyclically move said first duct from a position over said stackto a position remote from said stack through a predetermined path goingaway from said stack above a line initially parallel to the top of saidstack and causing said first duct to come to a substantial stop oversaid stack once each cycle, the sucking. action through said first ductcausing the top. sheet from said stack to be picked up by said arm andcarried by said arm to said remote position, means to remove from saidarm the sheet carried by said arm at said remote position, meansdefining a second duct fixedly positioned adjacent said stack andadjacent said predetermined path, said duct having an opening andrib-like members extending across. said opening, at least a part of saidrib-like members projecting away from the edge of one wall of said ductdefining a side of said opening in the plane of said wall, and means tosuck air in through said second duct, said second duct causing all thesheets but one carried by said pickup arm to drop off said pickup arminto a position substantially on top of said stack to be picked up bysaid pickup arm on the succeeding cycles thereof.

5. A material handling apparatus comprising means to hold a stack ofthin sheets, a pickup arm having a first duct defined in the endthereof, means to suck air in through said first duct, means to drivesaid arm to cyclically move said first duct from a position over saidstack to a remote position through a path which goes in a straight linefrom said position over said stack to said remote position and whichcurves away from. the top of said stack on the return from said remoteposition to a substantial stop position over said stack once each cycle,the sucking action through said first duct causing the top sheet fromsaid stack to be picked up by said arm and carried to said remoteposition, and means to remove the sheet carried by said arm from saidarm at said remote position, means defining a second duct having anopening adjacent said stack, means to suck air in through said opening,and ribs extending across said opening, part of said ribs projectingaway from the edge of the Wall of said duct defining the side of saidopening remote from said stack in the plane ofsaid Wall.

6. A material handling apparatus comprising means to hold a stack ofthin sheets, a pickup arm having a first duct defined in the endthereof, means to such air in through said first duct, means to drivesaid-arm to cyclically move to said duct from a position over said tionof said face being in direct contact with the spran stack to a remoteposition in a motion that brings said duct to a substantially completestop over said stack and in a path which goes in a straight line from aposition over said stack to said remote position and which curves awayfrom the top of said stack in return from said remote position to saidposition over said stack, the sucking action through said duct causingthe top sheet from said stack to be picked up by said arm and carried tosaid remote position, and means to remove from said arm the sheetcarried by said arm at said remote position, and means defining a secondduct adjacent said stack, and close but spaced from said path, ribsextending across said opening, part of said ribs proiecting away fromthe edge of the wall of said duct defining a side of said opening in theplane of said wall, said ribs being positioned in direct contact withthe side of said stack, and means to suck air through said second ductto cause all sheets but the one carried by said arm to be dropped fromsaid arm substantially on top of said stack in a position to be pickedup on the next succeeding cycles of said arm.

7. A material handling apparatus comprising means to hold a stack ofthin sheets, vacuum operated means to pick up one sheet at a time, meansto drive said vacuum operated pick up means to carry such sheet to aremote position in a predetermined path going away from said stack alonga line initially parallel to the top of said stack and cause said vacuumoperated pickup means to come to a substantial stop over said stack onceeach cycle, means defining a duct fixedly positioned alongside of saidstack and close to but spaced from said predetermined path, said ducthaving an opening adiacent said stack, means to suck air in through saidopening, a portion of the face of said opening making an acute anglewith a plane parallel to the sheets in said stack, said porside of saidstack, and means to suck air in through said duct to cause all of thesheets but one carried by said pickup means to be dropped from saidpickup means in a position substantially on top of said stack to bepicked up on the succeeding cycles of said pickup means.

8. A material handling apparatus as recited in claim further comprisingmeans to direct a stream of air against a side of said stack.

9. A material handling apparatus as recited in claim 4 wherein saidvacuum operated means comprises a pickup arm having two feet on the endthereof separated by a slot with ducts defined in said feet, means tosuck air in through said ducts, a pulley at a remote position, a

pair of belts coming together over said pulley, means to drive saidpickup arm to cyclically move said feet from a position over said stackto the point where said belts together with said feet straddling saidpulley.

10. A material handling apparatus comprising a means to hold a stack ofthin sheets, a vacuum operated pickup means adapted to pick up one sheetat a time from said stack and carry such sheet to a remote position,duct means defining an opening adjacent said stack, the face of saidopening having a curved portion, said curved porden of the face of saidopening being in direct contact with the side of said stack, means todrive said vacuum operated pickup means from a position above said stackin a predetermined path going away from the stack along a line initiallyparallel to the top of said stack, means for removing the sheet carriedto the remote position, a

portion of said opening being positioned close but spaced from saidpath, means to suck air in through the duct means to cause all thesheets but the one carried by said vacuum operated pickup means to bedropped from the last said means in a osition substantially on top ofsaid stack to be picked up by the vacuum operated pickup means onsucceeding cycles.

11. A material handling apparatus comprising a duct having an openingdefined therein, a portion of the face of said opening being curved,means to hold a stack of thin sheets with the edges of the main body ofsaid sheets against the side wall of said duct and the edges of thesheets in the top of said stack against the curved portion of the faceof said opening, and means to pick up one sheet at a time from the topof said stack and carry such sheet to a remote position, means to drivesaid means to pick up from a position above said stack in apredetermined path going away from the stack along a line initiallyparallel to the top of said stack, means for removing the sheet carriedto the remote position, a portion of said opening being positioned closebut spaced from said path, means to suck air in through the duct tocause all the sheet but the one carried by said means to pick up to bedropped from the last said means in a position substantially on top of aposition substantially on top of said stack to be picked up by the meansto pick up on succeedin cycles.

12. A material handling apparatus comprising a duct having an openingdefined therein, a portion of the face of said opening being curved,means to hold a stack of thin sheets with the edges of the sheets in thetop of said stack against the curved portion of the face of saidopening, means to suck air in through sm'd opening, and a vacuum pickuparm adapted to pick up one sheet at a time from the top of said stackand carry such sheet to a remote position, means to drive said vacuumoperated pickup arm from a position above said stack in a predeterminedpath going away from the stack along a line initially parallel to thetop of said stack, means for removing the sheet carried to the remoteposition, a portion of said opening being positioned close but spacedfrom said path, means to suck air in through the duct to cause all thesheets but the one carried by said vacuum operated pickup means to bedropped from the last said means in a position substantially on top ofsaid stack to be picked up by the vacuum pickup arm on succeedingcycles.

13. A material handling apparatus comprising a means to hold a stack ofthin sheets, a vacuum operated pickup means adapted to pick up one sheetat a time from said stack and carry such sheet to a remote position,duct means defining an opening adjacent said stack, the face of saidopening having a curved portion, said curved portion of the face of saidopening being in direct con tact with the side of said stack, means todrive said vacuum operated pickup means from a position above said stackin a predetermined nontortuous path going away from the stack, meansfor-removing the sheet carried to the remote position, a portion of saidopening being positioned close but spaced from said path, means to suckair in through the duct means to cause all the sheets but the onecarried by said vacuum operated pickup means to be dropped from the lastsaid means in said stack to be picked up by the vacuum operated pickupmeans on succeeding cycles.

14. A material handling apparatus comprising a duct having an openingdefined therein, a portion of the face of said opening being curved,means to hold a stack of thin sheets with the edges of the main body ofsaid sheets against the side wall of said duct and the edges of thesheets in the top of said stack against the curved portion of the faceof said opening, and means to pick up one sheet at a time from the topof said stack and carry such sheet to a remote position, means to drivesaid means to pick up from a position above said stack in apredetermined nontortuous path going away from the stack, means forremoving the sheet carried to the remote position, a portion of saidopening being positioned close but spaced from said path, means to suckair in through the duct to cause all the sheets but the one carried bysaid means to pick up to be dropped from the last said means in aposition substantially on top of said stack to be picked up by the meansto pick up on succeeding cycles.

15. A material handling apparatus comprising a duct 9 having an openingdefined therein, a portion of the face of said opening being curved,means to hold a stack of thin sheets with the edges of the sheet in thetop of said stack against the curved portion of the face of saidopening, means to suck air in through said opening, and a vacuum pickuparm adapted to pick up one sheet at a time from the top of said stackand carry such sheet to a remote position, means to drive said vacuumoperated pickup arm from a position above said stack in a predeterminednontortuous path going away from the stack, means for removing the sheetcarried to the remote position, a portion of said opening beingpositioned close 10 but spaced from said path, means to suck air inthrough the duct to cause all the sheets but the one carried by saidvacuum operated pickup means to be dropped from the last said means in aposition substantially on top of said stack to be picked up by thevacuum pickup arm on succeeding cycles.

References Cited in the file of this patent UNITED STATES PATENTS 101,040,025 Schlesinger Oct. 1, 1912 ;1,718,581 Rockstroh June 25, 19292,819,076 Wendt et a1. Ian. 7. 1958

1. A MATERIAL HANDLING APPARATUS COMPRISING MEANS TO HOLD A STACK OFTHIN SHEETS, A VACUUM OPERATED PICKUP MEANS, MEANS TO DRIVE SAID VACUUMOPERATED PICKUP MEANS TO CYCLICALLY MOVE SAID VACUUM OPERATED PICKUPMEANS FROM A POSITION OVER SAID STACK TO A POSITION REMOTE FROM SAIDSTACK IN A PREDETERMINED PATH GOING AWAY FROM SAID STACK ALONG A LINEINITIALLY PARALLEL TO THE TOP OF SAID STACK, SAID VACUUM OPERATED PICKUPMEANS COMING TO A SUBSTANTIAL STOP OVER SAID STACK ONCE EACH CYCLE ANDCAUSING THE TOP SHEET TO BE PICKED UP FROM SAID STACK BY SAID VACUUMOPERATED PICKUP MEANS AND CARRIED TO SAID REMOTE POSITION, MEANS TOREMOVE FROM SAID VACUUM OPERATED PICKUP MEANS THE SHEET CARRIED BY THELAST SAID MEANS AT SAID REMOTE POSITION, MEANS DEFINING A DUCT HAVING ANOPENING FIXEDLY POSITIONED ADJACENT SAID STACK AND CLOSE BUT SPACED FROMSAID PATH, AT LEAST A PORTION OF THE FACE